A 1st-year student at Trinity General School and member of the After-School Sweets Club. Her hobbies include searching for delicious sweets and tea parties. She has a gentle, airy personality and loves sweets dearly. Her love for chocolate mint is hardcore, to the point of buying bizarre items like 'chocolate mint cup ramen.' Having eaten too much of it, she became the first person infected with the Choco-Mint Virus, turning into the Choco-Mint Boss Zombie.

A 1st-year student at Trinity General School and member of the After-School Sweets Club. Her hobby is eating sweets 'normally.' She has a calm, quiet disposition and a cool personality that rarely shows emotion. While she often struggles being dragged into the eccentricities of her club mates, she takes pride in their daily life together. She wears a hoodie with cat ears over her uniform. Despite her cat-like personality and ears, she claims to dislike cats.

A 1st-year student at Trinity General School and member of the After-School Sweets Club. Her hobbies include romanticism and contemplation. She is a free-spirited, philosophical, and romantic girl who wants to share 'romance' with everyone, often confusing those around her with her mysterious words and actions. Her standards for romance are so broad they are incomprehensible, such as calling the club the 'After-School Sweets Gang' and acting like delinquents. She loves milk.

A 1st-year student at Trinity General School and member of the After-School Sweets Club. Her hobbies include events and visiting limited-edition sweets shops. She is a girl with wavy blonde hair in twin tails. Contrary to her ideal of being mature, her height and build are petite and childlike, leading others to treat her like a cute small animal. She snaps at such treatment, but even that is seen as cute. She is the club's tsundere but actually serves as the voice of reason, often acting as a brake when others go overboard. She was force-fed by Airi and became infected with the Choco-Mint Virus.

A 3rd-year student at Millennium Science School and President of Seminar. Her hobby is design. She has pale skin, long black hair, and wears black clothing with a contrasting white turtleneck. She is a top-tier scientist and engineer, possessing the highest overall capabilities in Millennium. She is an extreme rationalist who prioritizes the safety and interests of the district and Kivotos. While her intentions are good, she is a Machiavellian who accepts the sacrifice of the few for the happiness of the many. She struggles with interpersonal communication and empathy. Her private life is disastrous; she lives in a messy room and eats only convenience store bento and frozen foods for efficiency. She is currently working with Neru from a hideout to stop the virus.

A 3rd-year student at Millennium Science School and a member of C&C. Her hobby is victory. She wears a sukajan over her maid uniform. Despite her small stature, she has a fierce expression and behaves like a rough, high-pressure delinquent. Her height is her biggest sore spot. However, she has a strong sense of justice and hates bullying or illogical behavior. She never hurts people without reason and protects the weak. She has come to Trinity to find Seia at Rio's suggestion.

A 3rd-year student at Trinity General School and a member of the Tea Party. Her hobbies are reading and solving puzzles. Despite her youthful appearance, she is thoughtful, wise, and serious. She is a bookworm who frequents the Tea Party library and speaks in a complex, roundabout way filled with difficult wordplay. She can be cynical, and her way of speaking means people's understanding of her varies greatly.

A 3rd-year student at Gehenna Academy and Head Prefect of the Prefect Team. Her hobby is sleeping and resting. Her catchphrase is 'how bothersome,' and she has a lazy, weary aura, but she is strict about rules and has a strong sense of responsibility. She is an intelligent and sincere person who seems out of place in Gehenna, the school of 'freedom and chaos.' She is slightly high-strung, getting bothered if books on a shelf aren't aligned. She spends her days dealing with the endless incidents caused by Gehenna students.